Torque build up "off the line"

[anko]

Ah, should have explained. Nothing to do with regen braking or whatsoever. This parameter is just revealing the amount of pressure in the brake lines that run to the friction brakes.

When standing still (waiting for the next test to commence) this value will be greater than 0. So, the thought behind adding it to the graph is that when the value goes to 0 the test has started.

But once the test has started, there is no more need to read the value every sweep. In order to keep the sweep time as low as possible, I stop reading brake pressure once it has gone to 0. Problem is that I would have to restart my software in order to do a second test. So, I choose to skip the next 10 sweeps whenever the value goes to 0. Is the value still 0 after that, it will skip another 10 sweeps. Is it not 0, than it will continue to read the value every sweep. And so on. 10 sweeps is just a few seconds, so as long as I stand still for a few seconds at the beginning of the next test, the scanner software will have found a > 0 value and continue to read the value every sweep.

 

[Neverfuel]

Ah, should have explained. Nothing to do with regen braking or whatsoever. This parameter is just revealing the amount of pressure in the brake lines that run to the friction brakes.

When standing still (waiting for the next test to commence) this value will be greater than 0. So, the thought behind adding it to the graph is that when the value goes to 0 the test has started.

But once the test has started, there is no more need to read the value every sweep. In order to keep the sweep time as low as possible, I stop reading brake pressure once it has gone to 0. Problem is that I would have to restart my software in order to do a second test. So, I choose to skip the next 10 sweeps whenever the value goes to 0. Is the value still 0 after that, it will skip another 10 sweeps. Is it not 0, than it will continue to read the value every sweep. And so on. 10 sweeps is just a few seconds, so as long as I stand still for a few seconds at the beginning of the next test, the scanner software will have found a > 0 value and continue to read the value every sweep.

I get it now - you are compensating for time lag in the calcs. Makes sense. Is this all going to be captured in the EvBatMon App?

 

[anko]

One more attempt.

Properly spaced and on a linear scale. Every reading has its own timestamp now, instead of one timestamp per sweep. This results in a more true picture. All three graphs span 15 seconds, which should allow for good comparison.

Vertical red lines mark the timeframe in which my foot was moved away from the brake (to the throttle).

First is normal mode.
Second is charge mode.
Third is charge mode and pressing the throttle before ereleasing the brake.

Unfortunately, I ran out of runway on the third attempt, so that one was aborted @ 90 km/h :evil: :lol:

I thought these were going to be the last ones, but just now I realise that next to "Torque Delivered", I have also a parameter for "Torque Requested"

Personally, I like how these graphs demonstrate how afirst torque is constant and power increases and then, from approx 55 km/h power is constant and torque decreases. Especially the third seems to have captured that moment quite right .....

 

[gwatpe]

I think all data shows the constant torque to constant power transition quite well.

Really shows that we should not be too worried about the seemingly late startup of the ICE. During the first few seconds, all the power is coming from the battery, with the torque limiting dominating.

I have recorded some ICE starts with periods of higher acceleration, but these only resulted in petrol consumption as the generator was not seen to produce any electrical power.

If the ICE has operated just prior to the rapid acceleration period, I can see it helping out with the power needs, but if it was the first start, then power would be limited to the 60kW that the battery can supply, and this would affect any recorded data. I believe that successive acceleration tests are not showing what a driver normally experiences. The PHEV works well after the ICE has run for 20-30seconds. When it has not run at all before the period of rapid acceleration is when the driver notices a power shortage.

 

[jaapv]

Still, these curves do not indicate how Mitsubishi was able to improve the off the line performance so dramatically whilst maintaining the specifications. Rather the opposite.

 

[anko]

Really shows that we should not be too worried about the seemingly late startup of the ICE. During the first few seconds, all the power is coming from the battery, with the torque limiting dominating.

Interesting observation. Even before owning the car, simply by reading the spec sheets, I have always assumed that it would not make a difference whether the engine was pre-started or not, as indeed, at low speed that battery can produce all the power the E-motors can consume. From the graphs, it seems to make a very small difference but not something to worry about.

Also, the graphs show that even when stamping on the throttle, the engine does not start until you start moving (unless you are using Charge mode, of course). So, again something I reported earlier comes back to mind: While trying to tow the wheels of my caravan out of a little ditch, the engine started while I was not yet moving. I never understood why it would do that, as at 0 or very low speed the E-motors would not be able not handle the additional power anyway. Still don’t understand.

Unless there is a difference between standing still and standing still. With the brakes fully engaged, you may assumed the E-motors are near perfectly stopped. When trying to pull the caravan out of the ditch, some rocking may take place, resulting in a few revs from the E-motors.

Perhaps the combination of high torque demand + little revs of the E-motors trigger the engine startup. Or maybe the fact that the brakes are deployed stop the engine from starting up. Who knows …

I have recorded some ICE starts with periods of higher acceleration, but these only resulted in petrol consumption as the generator was not seen to produce any electrical power.

If the ICE has operated just prior to the rapid acceleration period, I can see it helping out with the power needs, but if it was the first start, then power would be limited to the 60kW that the battery can supply, and this would affect any recorded data. I believe that successive acceleration tests are not showing what a driver normally experiences. The PHEV works well after the ICE has run for 20-30seconds. When it has not run at all before the period of rapid acceleration is when the driver notices a power shortage.

How long was this period of “excessive acceleration, engine running but not electrical power generated by the generator”? Because I can imagine this happening when you accidentally and briefly cross the 60 kW threshold. But when you deliberately and for longer period cross the 60 kW threshold? I wonder. It would also be contradictory to MMC statement that they did not implement an EV only button for safety reasons: “an EV only button could would mean you have limited power available in an emergency situation”.

 

[anko]

Still, these curves do not indicate how Mitsubishi was able to improve the off the line performance so dramatically whilst maintaining tthe specifications. Rather the opposite.

Agreed. We need that MY16 data badly :mrgreen:

 

[jaapv]

Well, let's keep it at "allegedly improving the of-the-line performance dramatically" until we have a direct comparison between models and-or the new data. Blinde Maupie*... :roll:

* For our UK friends: "Adam and Eve"

 

[Fragge]

Ordered one of these:
http://www.dx.com/p/vgate-btwifi-icar-elm327-wi-fi-obd2-car-diagnosis-white-green-280025#.Vnkn0hXhC70
Looks like a direct copy of the one Anko is using, hopefully we can do the exact same tests on my 2016 model.

 

[jaapv]

Could be very interesting

 

[anko]

Ordered one of these:
http://www.dx.com/p/vgate-btwifi-icar-elm327-wi-fi-obd2-car-diagnosis-white-green-280025#.Vnkn0hXhC70
Looks like a direct copy of the one Anko is using, hopefully we can do the exact same tests on my 2016 model.

I hope not as mine was twice as expensive :evil: :lol: :lol:

Mine is a 2.1 versus this one a 1.5, btw.. Should not matter for what we need. If you want me to, sent me a PM with your mail address and I'll forward you the Java program I've used, as well as the XLSX sheet that allows you to make these graphs ....

 

[Barnfather]

Well, let's keep it at "allegedly improving the of-the-line performance dramatically" until we have a direct comparison between models and-or the new data.

Well when I get my PHEV I will be able to tell instantly, as the off-the-line performance of the demo car (prior years model) was awful - to the point of being potentially dangerous in certain situations I thought. The 'claim' by Mitsubishi that this has been fixed was the primary factor in putting an order in

 

[jaapv]

I cannot recognize that, my car is pretty quick off the mark, certainly more so than my previous Jaguar 2.2 D.

 

[greendwarf]

Neither can - nor can the boy Sarf Lundun racers I have left in my dust when required. I think the trick is not to expect a wheelie type take off from stopped but to get it rolling before quickly but steadily pressing the accelerator rather than just flooring it in one go. :twisted:

 

[Barnfather]

My problem was the 'lag', rather than the acceleration when moving.

This was most notable turning right onto a busy main road. That is where the standing start throttle response really needs to sing, and this wasn't the case.

I'm sure if you use the car day in day out it would be something you may sub-consciously compensate for so it may not be noticeable, but it was for me on a 3 day demo, and was pleased when I heard the MY16 car had addressed it.

 

[jaapv]

It is indeed a matter of anticipating, it soon becomes an automatism. Besides if a few tenths of a second can create a dangerous situation, I tend to wait for a safer moment.

 

[gwatpe]

I have to agree that we just need to wait for that slightly bigger gap in traffic. The hurry sickness we seem to suffer from has to be considered the problem and not really the car.

 

[jthspace]

I have never noticed an issue with acceleration from start, or even when driving; in fact if you want to have heart stopping bottom squeaking moments, drive a Smart car that faffs up its gear change at the same time the turbo lags as you pull onto the roundabout. I am a supporter of a 20 mph speed limit on roundabouts that is currently being discussed, just to save on the laundry bill.

Smarts are great town cars, but have their own "specialties" when driving! An earlier one I owned had the first speed limiter in the CPU removed (it had a second one as well which I left untouched) - and I could get 120 mph out of it which was fine, but roundabouts, that was a different story. Apparently you could get over 140 mph from it completely unrestricted. :shock:

The PHEV's are, what?, 1850 kgs kerb weight? and a big lump to get moving. I haven't been disappointed and, as Greendwarf said, I have also left other cars behind when pulling away thanks to the smooth constant acceleration.

Jeff

 

[rubes]

Hi all,

I hope I can add to this, I've had the benefit of having both versions of the phev (my14 was a company car chosen for the tax perks, and when I recently changed jobs I bought a my16 because I couldn't go back to an old noisy oil burner!) Anyway the new car definitely pulls harder from standstill but I'm not entirely convinced by the 2 second improvement claim in 0-25 times. My sister also currently has a my14 car and at the weekend we decided to do a rolling acceleration test from walking pace side by side. Yep mine is quicker! Not scientific by any means but I do have the experience of both.

And BTW the new model is probably 5% better in every area apart from electric range (no discernible difference) and the alloys, not sure about the black wheels...

 

[Carnut]

well I don't know what you (slow off the mark) blokes are on about.
I admit I haven't driven a new one, mine being a 6 month old 15 reg.
I took a friend for a trundle in PHEV and he owns a 5 series twin turbo oil burner which does 0-60 in about 6 seconds.
His comment when I floored the PHEV was "Bloody Hell!! that's quick." (& the ICE did not come in either)
I must admit I am driving like an old woman trying to see how much distance I can get out of it & I am always in eco mode.
But I must admit I have had no problems with takeoff at all. The 0-62 of 11 seconds is not brilliant (same as my 1.2 DSG Yeti) but I would say the 0-30 speed is exceptional for a two ton brick shaped tank!